Contrapositive Implication 7C080A
1. The problem asks for the contrapositive of the implication $ (p \lor q) \to r $.
2. Recall the contrapositive of an implication $ A \to B $ is $ \neg B \to \neg A $.
3. Here, $ A = p \lor q $ and $ B = r $.
4. Applying the contrapositive formula:
$$ \neg r \to \neg (p \lor q) $$
5. Using De Morgan's law, $ \neg (p \lor q) = \neg p \land \neg q $.
6. So the contrapositive is:
$$ \neg r \to (\neg p \land \neg q) $$
7. Now, let's compare with the options:
- Option 1: $ (\neg p \land \neg q) \to r $ (This is the converse of the contrapositive, not correct)
- Option 2: $ \neg r \to (\neg p \lor \neg q) $ (Incorrect because of $\lor$ instead of $\land$)
- Option 3: $ \neg r \to \neg (p \lor q) $ (This matches step 4, the contrapositive before applying De Morgan's law)
- Option 4: $ r \to (p \lor q) $ (This is the converse of the original implication, not correct)
8. Therefore, the contrapositive is exactly option 3: $ \neg r \to \neg (p \lor q) $.
Final answer: Option 3